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QuerySelectField正确显示查询但未保存在数据库中，提交时显示以下错误。

ProgrammingError: (ProgrammingError) can't adapt type 'Category' 'INSERT INTO articles (title, body, category, created) VALUES (%(title)s, %(body)s, %(category)s, %(created)s) RETURNING articles.id' {'category': <blog.models.Category object at 0x03A7E2D0>, 'body': u'Test', 'title': u'This is the New Post', 'created': datetime.datetime(2013, 10, 16, 14, 7, 23, 508000)}

在此处输入图像描述

当我输入标题和内容并通过从类别数据库中查询结果来选择显示的类别并尝试提交时，它会引发上述错误。

我知道我的错误是这一行

{'category': <blog.models.Category object at 0x03A7E2D0>

我怎么能把它弄对，我很想念。

表格.py

from models import DBSession
from models import Category
from wtforms import Form, TextField, TextAreaField, SubmitField, validators
from wtforms.ext.sqlalchemy.fields import QuerySelectField

def category_choice():
    return DBSession.query(Category)

class ArticleCreateForm(Form):
    title = TextField('Title', [validators.required(), validators.length(min=1,max=240)])
    body = TextAreaField('Content', [validators.required()])
    category = QuerySelectField('Category', query_factory=category_choice )
    submit = SubmitField()
    

class CategoryCreateForm(Form):
    name = TextField('Name', [validators.required(), validators.length(min=1,max=240)])
    description = TextAreaField('Description', [validators.required()])
    submit = SubmitField()

视图.py

@view_config(route_name='article_action', match_param='action=create', renderer='articles/create.jinja2')
def create(request):
    article = Article()
    category = Category()
    form = ArticleCreateForm(request.POST)
    if request.method == 'POST' and form.validate():
        form.populate_obj(article )
        DBSession.add(article, category)
        return HTTPFound(location=request.route_url('home'))
    return {'form':form, 'action':request.matchdict.get('create')}

模型.py

class Category(Base):
    __tablename__ = 'categories'
    id = Column(Integer, primary_key=True)
    name = Column(String(100), unique=True, nullable=False)
    description = Column(Text, nullable=False)

    def __unicode__(self):
        return self.name

class Article(Base):
    __tablename__ = 'articles'
    id = Column(Integer, primary_key=True)
    title = Column(String(255), unique=True, nullable=False)
    body =  Column(Text, nullable=False)
    category = Column(ForeignKey(Category.name), nullable=False)
    created = Column(DateTime, default=datetime.datetime.now)


    @property
    def slug(self):
        return urlify(self.title)

    @property
    def created_in_words(self):
        return time_ago_in_words(self.created)

创建.jinja2

{% extends 'base.jinja2' %}

{% block content %}
    <form action="{{ request.route_url('article_action', action='create') }}" method="post">
        {{ form.title.label }}
        {{ form.title }}<br/>

        {{ form.body.label }}
        {{ form.body }}<br/>

        {{ form.category.label }}
        {{ form.category }}<br/>

        {{ form.submit }}
    </form>
        <a href="{{ request.route_url('home') }}">Home</a>
{% endblock %}

完整回溯

Traceback (most recent call last):
  File "C:\Python27\lib\site-packages\pyramid_debugtoolbar\panels\performance.py", line 69, in noresource_timer_handler
    result = handler(request)
  File "C:\Python27\lib\site-packages\pyramid\tweens.py", line 21, in excview_tween
    response = handler(request)
  File "C:\Python27\lib\site-packages\pyramid_tm\__init__.py", line 82, in tm_tween
    reraise(*exc_info)
  File "C:\Python27\lib\site-packages\pyramid_tm\__init__.py", line 70, in tm_tween
    manager.commit()
  File "C:\Python27\lib\site-packages\transaction\_manager.py", line 111, in commit
    return self.get().commit()
  File "C:\Python27\lib\site-packages\transaction\_transaction.py", line 280, in commit
    reraise(t, v, tb)
  File "C:\Python27\lib\site-packages\transaction\_transaction.py", line 271, in commit
    self._commitResources()
  File "C:\Python27\lib\site-packages\transaction\_transaction.py", line 417, in _commitResources
    reraise(t, v, tb)
  File "C:\Python27\lib\site-packages\transaction\_transaction.py", line 389, in _commitResources
    rm.tpc_begin(self)
  File "C:\Python27\lib\site-packages\zope\sqlalchemy\datamanager.py", line 90, in tpc_begin
    self.session.flush()
  File "C:\Python27\lib\site-packages\sqlalchemy\orm\session.py", line 1818, in flush
    self._flush(objects)
  File "C:\Python27\lib\site-packages\sqlalchemy\orm\session.py", line 1936, in _flush
    transaction.rollback(_capture_exception=True)
  File "C:\Python27\lib\site-packages\sqlalchemy\util\langhelpers.py", line 58, in __exit__
    compat.reraise(exc_type, exc_value, exc_tb)
  File "C:\Python27\lib\site-packages\sqlalchemy\orm\session.py", line 1900, in _flush
    flush_context.execute()
  File "C:\Python27\lib\site-packages\sqlalchemy\orm\unitofwork.py", line 372, in execute
    rec.execute(self)
  File "C:\Python27\lib\site-packages\sqlalchemy\orm\unitofwork.py", line 525, in execute
    uow
  File "C:\Python27\lib\site-packages\sqlalchemy\orm\persistence.py", line 64, in save_obj
    table, insert)
  File "C:\Python27\lib\site-packages\sqlalchemy\orm\persistence.py", line 569, in _emit_insert_statements
    execute(statement, params)
  File "C:\Python27\lib\site-packages\sqlalchemy\engine\base.py", line 662, in execute
    params)
  File "C:\Python27\lib\site-packages\sqlalchemy\engine\base.py", line 761, in _execute_clauseelement
    compiled_sql, distilled_params
  File "C:\Python27\lib\site-packages\sqlalchemy\engine\base.py", line 874, in _execute_context
    context)
  File "C:\Python27\lib\site-packages\sqlalchemy\engine\base.py", line 1024, in _handle_dbapi_exception
    exc_info
  File "C:\Python27\lib\site-packages\sqlalchemy\util\compat.py", line 195, in raise_from_cause
    reraise(type(exception), exception, tb=exc_tb)
  File "C:\Python27\lib\site-packages\sqlalchemy\engine\base.py", line 867, in _execute_context
    context)
  File "C:\Python27\lib\site-packages\sqlalchemy\engine\default.py", line 324, in do_execute
    cursor.execute(statement, parameters)
ProgrammingError: (ProgrammingError) can't adapt type 'Category' 'INSERT INTO articles (title, body, category, created) VALUES (%(title)s, %(body)s, %(category)s, %(created)s) RETURNING articles.id' {'category': <blog.models.Category object at 0x03A7E2D0>, 'body': u'Test', 'title': u'This is the New Post', 'created': datetime.datetime(2013, 10, 16, 14, 7, 23, 508000)}
4

3 回答 3

3

你的问题出在这里：

form.populate_obj(article)

这基本上将表单字段值分配给数据库对象的相应字段。但是，您没有使用 SQLAlchemy relationship（您应该！），因此article.category需要包含类别的名称（为什么不是 ID？！）。但是，它QuerySelectField具有数据库对象（即Category实例）作为其值。

您有三个选择；第三个是首选：

  • 使用choices从数据库填充的普通 SelectField

  • 不要使用populate_obj，而是使用手动分配类别

    article.category = form.category.data.name
  • category将in 列重命名Article为 egcategory_name并使用relationship()soArticle.category不包含名称但包含Category对象。
于 2013-10-16T13:22:40.753 回答
1

您的文章模型中的类别关系不正确。它有两个问题：

  1. 您尚未提供该列的数据类型。
  2. Article.category 需要是关系，而不是列。

如果您将 Article 类修改为类似这样的内容，则应该会有所改进：

class Article(Base):
    ...
    category_name = Column(String(100), ForeignKey(Category.name), nullable=False)
    category = relationship(Category)

如果您这样做，SQLAlchemy 将知道类别属性必须是类别实例，并将根据需要自动加载和保存类别实例。

于 2013-10-16T13:26:15.010 回答
1

将关系添加到您的模型字段。

于 2013-11-14T07:20:23.273 回答